On this version of the game, the "Daily Challenge" system relies on the device's system clock. If you set your device date forward by one day, you can instantly unlock the next daily challenge. This was a famous exploit in the early days.
A retro-compatible Subway Surfers IPA rebuilt specifically to run smoothly on iOS 5.1.1 devices: classic endless-runner gameplay, tuned controls and visuals for legacy hardware, offline-first privacy-friendly design, and multiple installation options for non-App-Store distribution.
To get the game running, you are looking for a specific (the iOS app install file) that matches the hardware architecture of 2012.